Overlay with spinner

use a css3 class “spinner”. It’s more beautiful and you don’t need .gif

    .spinner {
       position: absolute;
       left: 50%;
       top: 50%;
       height:60px;
       width:60px;
       margin:0px auto;
       -webkit-animation: rotation .6s infinite linear;
       -moz-animation: rotation .6s infinite linear;
       -o-animation: rotation .6s infinite linear;
       animation: rotation .6s infinite linear;
       border-left:6px solid rgba(0,174,239,.15);
       border-right:6px solid rgba(0,174,239,.15);
       border-bottom:6px solid rgba(0,174,239,.15);
       border-top:6px solid rgba(0,174,239,.8);
       border-radius:100%;
    }
    
    @-webkit-keyframes rotation {
       from {-webkit-transform: rotate(0deg);}
       to {-webkit-transform: rotate(359deg);}
    }
    @-moz-keyframes rotation {
       from {-moz-transform: rotate(0deg);}
       to {-moz-transform: rotate(359deg);}
    }
    @-o-keyframes rotation {
       from {-o-transform: rotate(0deg);}
       to {-o-transform: rotate(359deg);}
    }
    @keyframes rotation {
       from {transform: rotate(0deg);}
       to {transform: rotate(359deg);}
    }

Exemple of what is looks like : http://jsbin.com/roqakuxebo/1/edit

You can find a lot of css spinners like this here : http://cssload.net/en/spinners/